Chronic non-healing (characterized by minimal or no scarring) and infected wounds continue to pose great challenges by burdening patients, wound care specialists, and the health care system. It is estimated that there are 1.1-1.8 million new chronic wound patients each year and approximately 8 million Americans suffer from chronic wounds. To make the situation worse, chronic wounds often predispose patients to infection. It is also not uncommon to have necrotic tissue on one side and epithelializing tissue on the other side. While wound treatments, such as debridement, can remove dead tissue and restart the healing process, such procedures can also damage healing tissue and delay healing. Therefore, a targeted and localized wound treatment is believed to substantially improve wound healing outcome. Unfortunately, such strategies are difficult to implement due to lack of effective methods to diagnose and monitor the wound healing status of different wound areas. There is an urgent and unmet need for the development of a new wound monitoring and diagnosis technique which is the focus of this investigation. Many biomolecules have been found to play an important role in wound healing responses. However, these biomolecules cannot be used as universal indicators of wound healing due to their large variation and instability among patients in different disease conditions. Many recent studies have shown that wound pH is a good indicator of wound conditions. Specifically, acidic environment provides fertile condition for cell proliferation, and angiogenesis while impeding bacterial growth. On the other hand, alkaline wounds impair cell growth while favoring bacterial colonization. We thus assume that a technology developed to detect wound pH and bacterial presence can be used as a means for quick wound diagnosis and monitoring healing. Taking advantage of the recent developments in optical imaging technology and our Phase I work, the overall goal of this Phase II project is to fabricate and then validate two new products ? pH-/bacteria-detecting diagnosis probe kit and pH-sensing wound dressing ? for non-healing/infected wound diagnosis and monitoring in human. For the development of such products, we will first optimize the condition for the fabrication of both products. This will maximize the ability of diagnosis kit to detect pH changes and bacteria presence and enable the wound dressing to map pH distribution in vitro (Aim 1). The in vivo efficacy of both diagnosis kits and wound dressing to detect chronic and infected wounds will be evaluated using porcine skin wound infection models (Aim 2). The products will then be evaluated in a pre-clinical study using discarded wound gauzes from patients with different wound condition and treatments (Aim 3). The work will allow us to develop new products for wound monitoring while gathering critical data to seek FDA approval towards commencement of human studies in the near future.